Dreadfully infectious human immunodeficiency virus (HIV) is still causing grave consequences. Vaccines are considered as the most effective and economic means for prevention from and therapy of viral infections. Unfortunately, the viruses like HIV, are comprised of many serotypes, and undergo rapid antigenic changes; these make it a grave challenge to produce an effective vaccine for cross protections.
For HIV-1, however, there are already 33 million infected individuals who each harbor a substantial array of HIV-1 quasi-species, which results in an enormous number of variants that are simultaneously seeded and circulating in the human population. Providing protection against this vast array of potentially infectious isolates is a challenge of unprecedented magnitude in vaccine development. Not surprisingly, the classical vaccine approaches of chemical inactivation or live attenuation have not produced a broadly protective or safe HIV-1 vaccine. So far, a vaccine against HIV is not available.